feat: add Jinja tester PySide6 simple app

Author: pwilkin

scripts/jinja/jinja-tester.py

@@ -0,0 +1,228 @@
+import sys
+import json
+import traceback
+from PySide6.QtWidgets import (
+    QApplication, QMainWindow, QWidget, QVBoxLayout, QHBoxLayout,
+    QLabel, QPlainTextEdit, QTextEdit, QPushButton
+)
+from PySide6.QtGui import QColor, QTextCursor, QTextFormat
+from PySide6.QtCore import Qt, QRect, QSize
+from jinja2 import Environment, TemplateSyntaxError, TemplateError
+
+
+# ------------------------
+# Line Number Widget
+# ------------------------
+class LineNumberArea(QWidget):
+    def __init__(self, editor):
+        super().__init__(editor)
+        self.code_editor = editor
+
+    def sizeHint(self):
+        return QSize(self.code_editor.line_number_area_width(), 0)
+
+    def paintEvent(self, event):
+        self.code_editor.line_number_area_paint_event(event)
+
+
+class CodeEditor(QPlainTextEdit):
+    def __init__(self):
+        super().__init__()
+        self.line_number_area = LineNumberArea(self)
+
+        self.blockCountChanged.connect(self.update_line_number_area_width)
+        self.updateRequest.connect(self.update_line_number_area)
+        self.cursorPositionChanged.connect(self.highlight_current_line)
+
+        self.update_line_number_area_width(0)
+        self.highlight_current_line()
+
+    def line_number_area_width(self):
+        digits = len(str(self.blockCount()))
+        space = 3 + self.fontMetrics().horizontalAdvance("9") * digits
+        return space
+
+    def update_line_number_area_width(self, _):
+        self.setViewportMargins(self.line_number_area_width(), 0, 0, 0)
+
+    def update_line_number_area(self, rect, dy):
+        if dy:
+            self.line_number_area.scroll(0, dy)
+        else:
+            self.line_number_area.update(0, rect.y(), self.line_number_area.width(), rect.height())
+
+        if rect.contains(self.viewport().rect()):
+            self.update_line_number_area_width(0)
+
+    def resizeEvent(self, event):
+        super().resizeEvent(event)
+        cr = self.contentsRect()
+        self.line_number_area.setGeometry(QRect(cr.left(), cr.top(), self.line_number_area_width(), cr.height()))
+
+    def line_number_area_paint_event(self, event):
+        from PySide6.QtGui import QPainter
+        painter = QPainter(self.line_number_area)
+        painter.fillRect(event.rect(), Qt.lightGray)
+
+        block = self.firstVisibleBlock()
+        block_number = block.blockNumber()
+        top = int(self.blockBoundingGeometry(block).translated(self.contentOffset()).top())
+        bottom = top + int(self.blockBoundingRect(block).height())
+
+        while block.isValid() and top <= event.rect().bottom():
+            if block.isVisible() and bottom >= event.rect().top():
+                number = str(block_number + 1)
+                painter.setPen(Qt.black)
+                painter.drawText(0, top, self.line_number_area.width() - 2,
+                                 self.fontMetrics().height(),
+                                 Qt.AlignRight, number)
+            block = block.next()
+            top = bottom
+            bottom = top + int(self.blockBoundingRect(block).height())
+            block_number += 1
+
+    def highlight_current_line(self):
+        extra_selections = []
+        if not self.isReadOnly():
+            selection = QTextEdit.ExtraSelection()
+            line_color = QColor(Qt.yellow).lighter(160)
+            selection.format.setBackground(line_color)
+            selection.format.setProperty(QTextFormat.FullWidthSelection, True)
+            selection.cursor = self.textCursor()
+            selection.cursor.clearSelection()
+            extra_selections.append(selection)
+        self.setExtraSelections(extra_selections)
+
+    def highlight_position(self, lineno: int, col: int, color: QColor):
+        block = self.document().findBlockByLineNumber(lineno - 1)
+        if block.isValid():
+            cursor = QTextCursor(block)
+            text = block.text()
+            start = block.position() + max(0, col - 1)
+            cursor.setPosition(start)
+            if col <= len(text):
+                cursor.movePosition(QTextCursor.NextCharacter, QTextCursor.KeepAnchor)
+
+            extra = QTextEdit.ExtraSelection()
+            extra.format.setBackground(color.lighter(160))
+            extra.cursor = cursor
+
+            self.setExtraSelections(self.extraSelections() + [extra])
+
+    def highlight_line(self, lineno: int, color: QColor):
+        block = self.document().findBlockByLineNumber(lineno - 1)
+        if block.isValid():
+            cursor = QTextCursor(block)
+            cursor.select(QTextCursor.LineUnderCursor)
+
+            extra = QTextEdit.ExtraSelection()
+            extra.format.setBackground(color.lighter(160))
+            extra.cursor = cursor
+
+            self.setExtraSelections(self.extraSelections() + [extra])
+
+    def clear_highlighting(self):
+        self.highlight_current_line()
+
+
+# ------------------------
+# Main App
+# ------------------------
+class JinjaTester(QMainWindow):
+    def __init__(self):
+        super().__init__()
+        self.setWindowTitle("Jinja Template Tester")
+        self.resize(1200, 800)
+
+        central = QWidget()
+        main_layout = QVBoxLayout(central)
+
+        # -------- Top input area --------
+        input_layout = QHBoxLayout()
+
+        # Template editor with label
+        template_layout = QVBoxLayout()
+        template_label = QLabel("Jinja2 Template")
+        template_layout.addWidget(template_label)
+        self.template_edit = CodeEditor()
+        template_layout.addWidget(self.template_edit)
+        input_layout.addLayout(template_layout)
+
+        # JSON editor with label
+        json_layout = QVBoxLayout()
+        json_label = QLabel("Context (JSON)")
+        json_layout.addWidget(json_label)
+        self.json_edit = CodeEditor()
+        json_layout.addWidget(self.json_edit)
+        input_layout.addLayout(json_layout)
+
+        main_layout.addLayout(input_layout)
+
+        # -------- Rendered output area --------
+        output_label = QLabel("Rendered Output")
+        main_layout.addWidget(output_label)
+        self.output_edit = QPlainTextEdit()
+        self.output_edit.setReadOnly(True)
+        main_layout.addWidget(self.output_edit)
+
+        # -------- Render button and status --------
+        btn_layout = QHBoxLayout()
+        self.render_btn = QPushButton("Render")
+        self.render_btn.clicked.connect(self.render_template)
+        btn_layout.addWidget(self.render_btn)
+        self.status_label = QLabel("Ready")
+        btn_layout.addWidget(self.status_label)
+        main_layout.addLayout(btn_layout)
+
+        self.setCentralWidget(central)
+
+    def render_template(self):
+        self.template_edit.clear_highlighting()
+        self.output_edit.clear()
+
+        template_str = self.template_edit.toPlainText()
+        json_str = self.json_edit.toPlainText()
+
+        # Parse JSON context
+        try:
+            context = json.loads(json_str) if json_str.strip() else {}
+        except Exception as e:
+            self.status_label.setText(f"❌ JSON Error: {e}")
+            return
+
+        env = Environment()
+        try:
+            template = env.from_string(template_str)
+            output = template.render(context)
+            self.output_edit.setPlainText(output)
+            self.status_label.setText("✅ Render successful")
+        except TemplateSyntaxError as e:
+            self.status_label.setText(f"❌ Syntax Error (line {e.lineno}): {e.message}")
+            if e.lineno:
+                self.template_edit.highlight_line(e.lineno, QColor("red"))
+        except Exception as e:
+            # Catch all runtime errors
+            # Try to extract template line number
+            lineno = None
+            tb = e.__traceback__
+            while tb:
+                frame = tb.tb_frame
+                if frame.f_code.co_filename == "<template>":
+                    lineno = tb.tb_lineno
+                    break
+                tb = tb.tb_next
+
+            error_msg = f"Runtime Error: {type(e).__name__}: {e}"
+            if lineno:
+                error_msg = f"Runtime Error at line {lineno} in template: {type(e).__name__}: {e}"
+                self.template_edit.highlight_line(lineno, QColor("orange"))
+
+            self.output_edit.setPlainText(error_msg)
+            self.status_label.setText(f"❌ {error_msg}")
+
+
+if __name__ == "__main__":
+    app = QApplication(sys.argv)
+    window = JinjaTester()
+    window.show()
+    sys.exit(app.exec())

scripts/jinja/requirements.txt

@@ -0,0 +1,2 @@
+PySide6
+jinja2